Ultrasound – Tutorials – Aorta

Many studies have demonstrated the accuracy of bedside ultrasound in detecting abdominal aortic aneurysm. Since the majority of these aneurysms occur distal to the renal arteries, it is imperative that the entire abdominal aorta (down to the aortic bifurcation) is visualized. Measurements should be taken across the widest diameter of aorta, from outer wall to outer wall.

• Is the aorta less than 3cm?
• Are the iliac arteries less than 1.5cm?

Curvilinear

1) Transverse – proximal aorta

• Visualize the aorta, inferior vena cava, lumbar shadow
• The superior mesenteric artery and splenic vein are often seen at this level

2) Transverse – mid aorta

• Visualize the aorta, inferior vena cava, lumbar shadow
• The renal arteries may sometimes be seen branching from the aorta at this level

3) Transverse – aortic bifurcation into iliac arteries

• The aorta bifurcates into iliac arteries around the level of the umbilicus (L4-5)
• The single circle of the aorta can be seen dividing with very small transducer movements (fanning motions of the transducer proximally and distally)

4) Longitudinal – mid aorta

• Be sure the aorta, and not the inferior vena cava, is centered on the screen

Abdominal aortic aneurysm with thrombus

Aortic dissection flap